SIST ISO 4793:1995

Name: SIST ISO 4793:1995 — Laboratory sintered (fritted) filters -- Porosity grading, classification and designation
SKU: SIST ISO 4793:1995
Price: 16200 RUB
Availability: InStock

Laboratory sintered (fritted) filters -- Porosity grading, classification and designation

Название (английский):

SIST ISO 4793:1995

Laboratory sintered (fritted) filters -- Porosity grading, classification and designation

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 9
Дата публикации:: 1 августа 1995 г.
ICS:: 71.040.20
Технический комитет:: I12 - Imaginarni 12 Imaginarni TC za ISO področje - vzdrževani privzeti ISO standardi

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Язык документа:

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Цена:16 200 ₽

Описание (английский):

Filters are graded according to their pore size index in one of the eight classes specified. This is applicable to laboratory filters made of glass, vitreous silica, ceramics, metals and plastic materials. Annex A specifies a method for determination of pore size index. Annex B and C concern with a procedure for assessing uniformity of filters and for determination of air permeability.

Abstract

Похожие стандарты

Упомянутые в описании и другие стандарты SIST

Overview

ISO 4793:1980 defines a standardized system for grading, classifying and designating laboratory sintered (fritted) filters by their porosity. Applicable to filters made of glass, vitreous silica, ceramics, metals and plastics, the standard divides filters into eight porosity classes (designated P1.6 through P250) based on a measured pore size index (expressed in micrometres). It also includes test procedures for assessing filter uniformity and measuring air permeability (Annexes A, B and C).

Key topics and requirements

Porosity grading and designation: Filters are assigned to one of eight classes. The grade designation uses the letter P followed by the upper limit of the pore size index in micrometres (for example, P16).

Pore size index (Annex A): A bubble-pressure method measures the air pressure at which the first air bubble breaks free from a wetted filter; this pressure is converted to an equivalent pore size index. The method specifies choice of test liquids (e.g., water, isopropanol, lower surface‑tension liquids) and precautions for wettability and chemical reactivity.

Uniformity assessment (Annex B): After the initial bubble-pressure reading, the filter can be checked for uniform pore distribution across the working area by increasing pressure and observing bubble emergence across the surface.

Air permeability (Annex C): A flow measurement at a specified pressure differential (e.g., 1 mbar) determines permeability. The standard provides methods to calculate air flow per unit area and requires minimum permeability values by grade (see Annex C / Table 2).

Quality expectations: Filters must not shed particles under normal use and should withstand a working pressure differential of 1.013 bar. Manufacturers are recommended to aim for pore size indexes near the centre of each grade range.

Applications

Select appropriate fritted laboratory filters for sample preparation, filtration and analytical workflows.

Define acceptance criteria and quality control tests for production of sintered filters (glass, ceramic, metal, plastic).

Specify filter performance (pore size index, uniformity, permeability) in procurement documents and technical datasheets.

Support laboratory equipment manufacturers and filtration accessory suppliers in consistent product classification.

SIST ISO 4793:1995

Abstract

Похожие стандарты

Overview

Key topics and requirements

Applications

Who should use this standard

Related standards

Технические детали

ISO 4793:1980

Laboratory sintered (fritted) filters — Porosity grading, classification and designation

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